Nightmare removing 3 jaw chuck

Hello Mark, hope you get the chuck back on OK and to your satisfaction.If it all goes well, it would be easier next time to turn up a temporary centre in the 3 jaw rather than disturbe it. If you take it out, and want to reuse it, a quick skim and you are away again. Cheers.

Hello Mark. I have just experienced the same problem that you had with your mini lathe 3 jaw chuck. I managed to remove it using the jacking method, undoing each nut in turn pressed against a brass shim. The chuck eventually popped off the protrusion in the spigot backplate. Now I have the problem that I cannot replace the 3 jaw chuck nor a collet chuck as neither will slip onto the spigot backplate protrusion. How did you resolve your problem? I am considering three options, 1. Contact the supplier (I bought the lathe 6 weeks ago), 2. Apply emery cloth to the edge of the protrusion whilst the lathe turns 3. Attempt to turn a thou off the protrusion. Oh what to do?

New lathe? Contact the supplier and do not make any 'home' modifications if you want the warranty to remain in place!

You really need to know whether the spigot is oversize or the fitted items undersized.

Jason's suggested method of removal clearly works. An alternative for the future, if sufficient space, for a long term fix with still tight fitment, might be to thread three holes in the mounting plate (equally spaced to avoid balance issues) and use these to jack off the item fit

ted.

Tight fit is certainly better than loose, but there are practical limits....

Your third option is fraught with danger. "Attempting" does not instill confidence. Any failure (taking off too much) would be a very poor outcome.

They can be replaced by using the nuts to pull the chuck back on. You could then think about the modification I showed.

Thank you for the advice. I'm new to using lathes and having spent six weeks reading and reading, I decided today to 'have a go' at stripping the lathe to give it a good clean. This is when I hit upon how difficult it was to remove the chuck. The backplate protrusion is 55.07mm and the chuck recess is 55mm. I will heed everyone's warning and will contact the supplier for advice. They are very reputable. Mark, I'll let you know how I get on. (I have also sent you a direct message with extra information).

Edited By Andrew Dolinski on 01/03/2017 22:12:51

I have always thought that was normal!

How tight a fit should the chuck be?

I like the recommendation by Francis IoM should I have no luck with the supplier. Using the chuck or the spare face plate with some polish/lapping compound could well reduce the over tight fit. However as Howi has asked how tight should the fit be? Mine surely is too tight.

I doubt this is a fault.

The chuck on my mini-lathe was very tight on the register when the lathe was new but it got much better after the chuck had been on and off several times.

The manual that came with my WM280 mentions that the chuck will be tight on a new lathe. Again normal swapping between the 3 and 4 jaw chucks soon cured the problem. At first, I had to use the 'jacking off' trick: but not for long.

When removing the chuck you have to be careful to push it off the register evenly. The chuck is liable to wedge if one side moves out faster than the other, and it may be necessary to tap the chuck back with a rubber mallet to straighten it before trying again.

'Wearing in' the register as described made no difference to the run-out on either my mini-lathe or the 280.

I suppose the degree of tightness between lathes will vary within manufacturing tolerances. Some could be noticeably tighter than others.

Dave

Hi everyone,

Nice to know that I am not the only one whose chuck gets locked on.Mine often does and I no longer use the back gear to lock the spindle,I lost too many teeth that way.Now,I just clamp a piece of hard wood in the chuck and give it a whack with a lump hammer [the wood,that is,not the chuck! ] Most times it works [mine is a screw on chuck ]

Talking about backup from suppliers !!!! tell me about them !.Once they sell you something,you,re on your own.

If you have a problem later on,you will be told "Sorry,we no longer stock that machine/item/part,or whatever. I,ve been there,had that from some of the biggest suppliers in Model Engineer.,who shall be nameless.

While I,m on my soapbox,does anyone know where I can get a gauge for grinding tool bits for Acme threads ? I know they can be had from America for about 9 dollars but they want 35 dollars extra to post one on. No kidding.,Seems a lot of money for a little bit of tin plate.

.

Before spending $44, I would see what I could do with the piercing saw and a file.

MichaelG.

How about this .

HTH,

Rod

That seems pretty fair, Rod

MichaelG.

Or significantly cheaper from Chronos

Or even cheaper from Proops.

'screw cutting gauge' is the search you need.

Or you want push, you could go for the M&W version from Myford or from Machine DRO

Neil

Edited By Neil Wyatt on 03/03/2017 18:06:58

It would be interesting to compare the quality of these items, Neil

The two M&W ones are, hopefully, near-identical ... but the others appear to vary.

... How about doing an impartial review in MEW ?

MichaelG.

As I'm sure you would expect the Editor of MEW has both M&W and economy versions in his 'toolroom'.

A detailed comparative review will appear in MEW 253. Enough to say there are several differences and each has aspects that are better than the other. But which is the better? The only way to find out will be to wait for MEW 253

Neil

^^^

Well done, Sir

MichaelG.

I bought an M&W no 200 from a reputable supplier many years ago and recall sending it back for a replacement on the ground that the stamped markings on this far from cheap item were askew.

I note that on this combination gauge you get female vees for all but the acme angle. The Starrett acme "gage" does provide a vee together with pitch gauges and the useful information that the depth of thread is half the pitch + 0.010".

I have never seen much point in the male vee that some gauges feature; any ideas?